No way to make hardware ones work. Brightness, volume and mediaplayer keys work OK. For touchpad toggling consider using my desktop-scripts: [https://github.com/pfactum/desktop-scripts]

+

Fn keys work out of the box. Three extra keys on the top right side are not working and require either dell-wmi driver patching (work in progress [http://lkml.iu.edu/hypermail/linux/kernel/1711.2/02894.html]) or DSDT mangling.